Self-propelled walk power mowers are well known for cutting grass. For example, such mowers are commonly used by property owners, such as homeowners, to cut their lawns. Such mowers have a cutting deck that houses a rotary grass cutting blade. The deck is supported by a plurality of wheels for rolling over the ground. A handle extends upwardly and rearwardly from the deck. A user who walks on the ground behind the deck grips a handle grip of the handle to manipulate and guide the mower during a grass mowing operation.
It can be difficult or is undesirable for some users to manually push a walk power mower over the ground in order to cut one's lawn. It is tiring to do so, particularly when the area being mowed is either large, hilly, or both. Thus, many mowers have traction drive systems that utilize part of the power generated by the prime mover carried on the mower to drive at least one pair of the mower's wheels, either the front wheels or the rear wheels, in a forward direction. Such a self-propelled mower relieves the user of the necessity of having to bodily push the mower over the ground. This greatly eases the physical effort required from the user in mowing one's lawn. The user now primarily guides or steers the mower during the powered forward motion provided by the traction drive system and the prime mover.
There are times when mowing one's lawn when the user needs to pull the mower in reverse at least over short distances. For example, when a user cuts grass under the branches of a bush, the user will ordinarily drive the mower forwardly so that the cutting blade reaches under the branches sufficiently to cut whatever patch of grass lies beneath the branches. However, once this patch of grass is cut, the user must pull back on the handle to pull the mower out from under the branches of the bush. While the traction drive system is designed with a one way clutch to allow the drive wheels to free-wheel during reverse motion so that the user is not pulling back against the resistance provided by the gearing in the traction drive system, the drive wheels of the mower are typically unpowered during this reverse motion.
As a result, many users end up having to manhandle or wrestle the mower back in this reverse motion scenario. This requires the user to expend physical energy and for some users accomplishing manual reverse motion of the mower may be difficult or impossible in some situations. This difficulty is exacerbated for those users in which trimming operations requiring reverse motions of the mower are numerous or are required on difficult terrain. For example, in trimming beneath a bush, pulling back on the mower is even more difficult if the user has to pull the mower back up a slope to get it out from under the branches of the bush. Accordingly, it would be an advance in the art to provide a reliable, durable, and cost effective traction drive system that provides powered motion of a walk power mower in both forward and reverse directions.